I need some expert advice on geraniums (Pelargoniums). I have several quite old plants that live in the office, in a south facing window. They get extremely leggy, crawling up the window, etc. They bloom almost continuously. One deep pink, one white, one salmon. I don't know when/how to cut them back to get them to be a bit more compact. I think (think, don't know) the white one is a trailing variety (like you see spilling down out of window boxes). I really love these plants and I'm afraid of cutting them back at the wrong time and killing them. Help, Oh Goddess of Geraniums!

"Goddess of geraniums" oh my!

I cut mine back in January, way back to about 2-3 inches high. I know it sounds drastic. Some of the cuttings are started for new plants. If you have space in your greenhouse and can keep it from freezing that would be the ideal place to put your pots of old plants. If you don't have a place with better light than your office, it wouldn't hurt to wait a while because new sprouts would get leggy really fast. I usually change about half the container soil when I cut them back. If using a mix with fertilizer I only use plain water. Around mid summer I use some fertilizer in the water because by then they have used up whatever came in the mix. In the fall after the first frost I dig the ones out of the big planters and move the smaller containers into the greenhouse for the winter. The more common Pelargoniums will handle 25 degrees but the Martha Washington ones are not as hardy. The plants get very little care in winter, just a light watering every few weeks.

The plants I dig out of the big planters are just plopped down into boxes lined with old potting soil bags. No extra soil, just what comes out on the roots. Usually they bloom before I get them cut back and replanted. They are tough. I'm late with the cutting back this year but I don't think it will make much difference.

If you have one with smaller more ivy shaped leaves and is stiffer and more "waxy, it might be a trailing variety. I have no experience with those because the wind rips apart any hanging plants I have tried.

I hope this helps.

Thanks Mary, this was GREAT HELP! I will wait and cut mine back a bit later so that the sprouts won't get so leggy. The greenhouse is unheated so that's a no-go. I did not know about changing the soil when cutting back, so I will definitely do that. I've been able to take a few cuttings now and then, but most of my geranium cuttings do not root, no matter how I try. I'll keep trying! I don't have the waxy leaved type you mention (I had a lovely one but it only survived one summer). Around here, most geraniums are treated as annuals for pots/planters, but I'd really like to try to keep mine going year on year, especially when I get one that's a more unusual color (than red). The white one that I have is not like any other geranium I've ever seen/grown. It really grows fast and very big and flowers nonstop.